9781934874127-ch25

Paddlefish Management, Propagation, and Conservation in the 21st Century

Influence of Cladoceran Composition and Abundance on Survival of Age-0 Paddlefish

Steven R. Chipps, H. Denise Symens, and Herbert Bollig

doi: https://doi.org/10.47886/9781934874127.ch25

Abstract.—We evaluated the influence of prey composition and abundance on survival and growth of age-0 paddlefish Polyodon spathula in 0.5-ha rearing ponds. Cladoceran abundance was measured in the spring of 1999 (n = four ponds), 2000 (n = six ponds) and 2005 (n = five ponds) at Gavin’s Point National Fish Hatchery, South Dakota. Using an information theoretic approach, we found that density of small cladocerans (e.g., Bosmina) at the time of larval stocking was the best supported model in explaining paddlefish survival. In contrast, estimates of Daphnia abundance (initial, mean, and maximum density) were poor predictors of paddlefish survival. Neither the magnitude of Daphnia abundance nor whether abundance was increasing or decreasing in the ponds after stocking appeared to influence paddlefish survival. Paddlefish growth, however, was positively related to mean Daphnia abundance in ponds. These patterns highlight the need to better understand larval feeding ecology of paddlefish and the role of electrosensory detection as it relates to prey composition and abundance.